Rose La Viola of New Canaan. Contributed She drives herself—always accompanied and at times of light traffic—doesn’t own a walker or cane, and prefers to take the stairs up and down from her quarters at Schoolhouse Apartments on South Avenue, shunning the elevator. She’s one of the senior living facility’s most active, social residents, an avid ballroom dancer who participates in multiple activities, according to Administrator Tatiana DeJesus. “She loved Tai Chi,” DeJesus recalled. And on Friday, she turns 100—a milestone that those close to La Viola are preparing to celebrate even as they admit the number itself belies her vitality.